1. Field of the Invention
The invention generally relates to an improved manufacturing method for the hole-punching assembly of a hole-punching unit. More particularly, the invention relates to an improved manufacturing method that can simplify the production process and lower the production cost and is different from the prior art manufacturing method, which is characterized with a more difficult production process and results in a higher production cost. Therefore, the method of the present invention has a higher level of economic value and usefulness.
2. Description of the Related Art
Multiple-hole punching devices have been used to punch holes on a stack of paper so that the paper may be bound into a book through the holes. Because such a device has a plurality of punching pieces, it needs additional components that can hold a stack of paper and set it into a neat condition so that the punching operation may be carried out smoothly.
Please refer to FIGS. 1 and 2. FIG. 1 is a perspective view showing the overall structure of the hole-punching unit of the prior art. FIG. 2 is a partial sectional view showing the hole-punching unit of the prior art.
The hole-punching unit 20 of the prior art has a row of slots 21, two retaining plates 211 and 212, a grip portion 23, two rods 24, a positioning piece 25, two elastic elements 241 and a plurality of punching pieces 30, A gap 22 for the insertion of a stack of paper is transversely disposed. The slots 21 are separated by a row of ribs. The two retaining plates 211 and 212 are fitted on by bolts. The grip portion 23 is provided on one side of the hole-punching unit 20 so that a user may use the grip portion 23 to fit the unit 20 into a hole-punching machine or take it out from such machine. The two rods 24 are disposed in the two sides of a rear portion of the unit 20. The positioning piece 25 is fitted on the unit 20 with the two rods 24. Each rod goes through an elastic element 241; the proximal ends of the elastic elements 241 press against the unit 20, and the distal ends of the elastic elements 241 press against the positioning piece 25.
The punching pieces 30 may go through and be held in the row of slots 21. A retaining plate 251 is also provided so as to hold the punching pieces 30 in place. If a different number of holes is wanted, a user may unfasten the retaining plate 251 and then take out or add one or more of the punching pieces 30. If the slots 21 have a rectangular shape, the punching pieces 30 should have a rectangular shape. The punching pieces 30 may have different shapes—rectangular, triangular, circular, etc.
The hole-punching unit 20 of the prior art has the following eight disadvantages:
1. The hole-punching unit 20 of the prior art is made of iron and is relatively bulky, hence, more material is needed in its production.
2. The hole-punching unit 20 of the prior art is made of iron, therefore, it is quite heavy. This causes inconvenience in the production process and transport.
3. Because the unit 20 is larger in size and heavier in weight after it is integrally formed, the processing of its gap 22 and slots 21 requires a bigger machine and is relatively more difficult to carry out and more time-consuming. Therefore, the processing cost is higher.
4. Such manufacturing method can only allow the shapes of the slots to be rectangular, triangular or diamond shape (not circular).
5. To cover and protect the slots 21, the two retaining plates 211 and 212 are provided. Hence, the production cost of such unit 20 is high and such a unit 20 has a lower economic value.
6. In the prior art, to make the production process easier to carry out, the unit 20 comprises two halves, which are joined together by screws or bolts. Even so, the disadvantages (such as heavy weight and the processing of the slots 21 being difficult to carry out) still remain.
7. Though there are different types (as according to the shapes of the punching pieces) of the unit 20, their production cost and hence their selling prices are relatively high due to said disadvantages.
8. Because the unit 20 of the prior art is integrally formed and its slots 21 and paper gap 22 require processing, a higher degree of precision in the production and processing is needed; if any of its part is slightly imperfect or imprecise, the operation of the whole unit 20 would be greatly affected and sometimes the whole unit 20 has to be discarded. This constitutes a waste.
Therefore, the disadvantages (such as the high production cost and the difficult production process) of the hole-punching unit 20 of the prior art need to be overcome and its manufacturing method improved. The method of the present invention may be used to overcome these disadvantages as well as to bring up the efficiency in production and enhance the economic value.
To eliminate the disadvantages of the prior art, the inventor has put in a lot of effort in the subject and has successfully come up with the improved manufacturing method for the hole-punching assembly of a hole-punching unit of the present invention. The manufacturing method of the present invention can lower the production cost and simplify the production process of the hole-punching assembly as well as enhance the efficiency in production.